package edu.jamestang.yeb.config;

import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.simp.config.ChannelRegistration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.messaging.simp.stomp.StompCommand;
import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
import org.springframework.messaging.support.ChannelInterceptor;
import org.springframework.messaging.support.MessageHeaderAccessor;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;

/**
 * @author JamesTang
 * @date 2021/12/29 18:15
 */
@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

    @Value("{tokenHead}")
    private String tokenHead;

    @Autowired
    private JwtTokenUtil jwtTokenUtil;

    @Autowired
    private UserDetailsService userDetailsService;


    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/ws/ep").setAllowedOrigins("*").withSockJS();
    }

    @Override
    public void configureClientInboundChannel(ChannelRegistration registration) {
       registration.interceptors(new ChannelInterceptor() {
           @Override
           public Message<?> preSend(Message<?> message, MessageChannel channel) {
               StompHeaderAccessor accessor = MessageHeaderAccessor.getAccessor(message, StompHeaderAccessor.class);
               assert accessor != null;
               if(StompCommand.CONNECT.equals(accessor.getCommand())){
                   String token = accessor.getFirstNativeHeader("Auth-Token");
                   if(!StringUtils.isEmpty(token)){
                       String authToken = token.substring(tokenHead.length());
                       String username = jwtTokenUtil.getUserNameFromToken(token);
                       if(!StringUtils.isEmpty(username)){
                           UserDetails userDetails = userDetailsService.loadUserByUsername(username);
                           if(jwtTokenUtil.validateToken(authToken,userDetails)){
                               UsernamePasswordAuthenticationToken authenticationToken = new UsernamePasswordAuthenticationToken(userDetails, null, userDetails.getAuthorities());
                               SecurityContextHolder.getContext().setAuthentication(authenticationToken);
                           }
                       }
                   }
               }
               return message;
           }
       });
    }

    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        registry.enableSimpleBroker("/queue");
    }
}
